We don't have enough information yet, and I want to stress that my theory
on 780 is just that - neither Ross nor I have encountered a broken one yet.
On Thu, Jun 27, 2013 at 11:20 AM, ET <sketchfoot.gmail.com> wrote:
> Are they "broken" only in terms of AMBER? Or could this be classed as a
> general hardware fault pertaining to all applications that use the card?
>
>
>
>
> On 27 June 2013 18:50, Scott Le Grand <varelse2005.gmail.com> wrote:
>
> > It's not really a question of how it's programmed, it's a question of
> > manufacturing. One picks 12 out of 15 processor cores on the chip
> itself
> > to make a GTX 780 as opposed to picking 14 out of 15 processor cores to
> > make a GTX Titan. In the former, there are 455 ways to do so and in the
> > latter, 15.
> >
> >
> >
> >
> >
> >
> > On Wed, Jun 26, 2013 at 7:13 PM, ET <sketchfoot.gmail.com> wrote:
> >
> > > Thanks very much for the quick information guys! It's much appreciated.
> > >
> > > I'm not that up on the manner in which these cards are programmed, so
> am
> > a
> > > little confused by your explanation Scott. could you please clarify it
> > for
> > > me?
> > >
> > > br,
> > > g
> > >
> > >
> > > On 27 June 2013 01:47, Scott Le Grand <varelse2005.gmail.com> wrote:
> > >
> > > > To clarify, there are 15 SMXs in a GK110 GPU. For GTX Titan, one of
> > them
> > > > is disabled. There are 15 (15 choose 1) ways to do this. All of
> them
> > > seem
> > > > to be broken.
> > > >
> > > > There are 12 out of 15 active SMXs in GTX 780. That means there are
> 455
> > > (15
> > > > choose 3) ways to make one. I'm a little nervous that some of those
> > > > configurations may be broken, so the best thing to do is to test if
> > they
> > > > exhibit deterministic behavior upon acquiring them, and if they
> don't,
> > > RMA
> > > > them as defective.
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > > On Wed, Jun 26, 2013 at 4:31 PM, Ross Walker <ross.rosswalker.co.uk>
> > > > wrote:
> > > >
> > > > > Hi All,
> > > > >
> > > > > Ok, good news on the GTX780 front. After 4 days of testing neither
> > > Scott
> > > > > nor myself have been able to break the GTX780s. This is in a 4 x
> > GTX780
> > > > > Exxact system although at present we have only tested multiple
> single
> > > GPU
> > > > > runs using all 4 GPUs at once - I.e. pmemd.cuda (NOT
> pmemd.cuda.MPI)
> > -
> > > I
> > > > > will be testing pmemd.cuda.MPI shortly but I don't see why this
> > > wouldn't
> > > > > work given single GPU is working fine.
> > > > >
> > > > > Key though is that there are multiple ways to build GTX780s, and
> for
> > > now
> > > > > we have only tested one specific model which is as follows:
> > > > >
> > > > > http://tinyurl.com/prxlwy6 Zotac GTX780 ZT-70201-10P
> > > > >
> > > > >
> > > > > Until we have an opportunity to test different vendor GTX780s and
> OC
> > > > > versions the advice is to stick with the above model if you can.
> > > > >
> > > > > All the best
> > > > > Ross
> > > > >
> > > > > /\
> > > > > \/
> > > > > |\oss Walker
> > > > >
> > > > > ---------------------------------------------------------
> > > > > | Associate Research Professor |
> > > > > | San Diego Supercomputer Center |
> > > > > | Adjunct Associate Professor |
> > > > > | Dept. of Chemistry and Biochemistry |
> > > > > | University of California San Diego |
> > > > > | NVIDIA Fellow |
> > > > > | http://www.rosswalker.co.uk | http://www.wmd-lab.org |
> > > > > | Tel: +1 858 822 0854 | EMail:- ross.rosswalker.co.uk |
> > > > > ---------------------------------------------------------
> > > > >
> > > > > Note: Electronic Mail is not secure, has no guarantee of delivery,
> > may
> > > > not
> > > > > be read every day, and should not be used for urgent or sensitive
> > > issues.
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > > _______________________________________________
> > > > > AMBER mailing list
> > > > > AMBER.ambermd.org
> > > > > http://lists.ambermd.org/mailman/listinfo/amber
> > > > >
> > > > _______________________________________________
> > > > AMBER mailing list
> > > > AMBER.ambermd.org
> > > > http://lists.ambermd.org/mailman/listinfo/amber
> > > >
> > > _______________________________________________
> > > AMBER mailing list
> > > AMBER.ambermd.org
> > > http://lists.ambermd.org/mailman/listinfo/amber
> > >
> > _______________________________________________
> > AMBER mailing list
> > AMBER.ambermd.org
> > http://lists.ambermd.org/mailman/listinfo/amber
> >
> _______________________________________________
> AMBER mailing list
> AMBER.ambermd.org
> http://lists.ambermd.org/mailman/listinfo/amber
>
_______________________________________________
AMBER mailing list
AMBER.ambermd.org
http://lists.ambermd.org/mailman/listinfo/amber
Received on Thu Jun 27 2013 - 12:00:02 PDT
